function sunb() {
	var width = 960,
		height = 700,
		radius = Math.min(width, height) / 2,
		color = d3.scale.category20c();

	var svg = d3.select("#sunburst").append("svg")
		.attr("width", width)
		.attr("height", height)
		.append("g")
		.attr("transform", "translate(" + width / 2 + "," + height * .52 + ")");
	
	var partition = d3.layout.partition() //分区图,可方可圆
		.sort(null)
		.size([2 * Math.PI, radius * radius])
		.value(function(d) {
			return 1;
		});

	var arc = d3.svg.arc()
		.startAngle(function(d) {
			return d.x;
		})
		.endAngle(function(d) {
			return d.x + d.dx;
		})
		.innerRadius(function(d) {
			return Math.sqrt(d.y);
		})
		.outerRadius(function(d) {
			return Math.sqrt(d.y + d.dy);
		});

	d3.json("flare.json", function(error, root) { // 三层
//	d3.json("flare1.json", function(error, root) { // 多层
		if(error) throw error;

		var path = svg.datum(root).selectAll("path")
			.data(partition.nodes)
			.enter().append("path")
			.attr("display", function(d) {
				return d.depth ? null : "none";
			}) // hide inner ring
			.attr("d", arc)
			.style("stroke", "#fff")
			.style("fill", function(d) {
				return color((d.children ? d : d.parent).name);
			})
			.style("fill-rule", "evenodd")
			.each(stash);
	
		d3.selectAll("input").on("change", function change() {
			var value = this.value === "count" ?
				function() {
					return 1;
				} :
				function(d) {
					return d.size;
				}; //根据size,count选项确定比例

			path.data(partition.value(value).nodes)
				.transition()
				.duration(1500)
				.attrTween("d", arcTween);
		});
	});
	
	// Stash the old values for transition.
	function stash(d){
		d.x0 = d.x;
		d.dx0 = d.dx;
	}
	
	// Interpolate the arcs in data space.
	function arcTween(a)
	{
		var i = d3.interpolate({x:a.x0, dx:a.dx0},a);
		return function(t){
			var b=i(t);
			a.x0 = b.x;
    		a.dx0 = b.dx;
    		return arc(b);
		};
	}
	d3.select(self.frameElement).style("height",height+"px");

}
sunb();